My experience is that basically, if you actually want to do anything meaningful with video, you need to host your own instance, because no one wants to be beholden to the bandwidth, especially if it gets any uptake. In which case, obviously, you're on your own for the costs. The only way I can see PeerTube working is if a few of the medium size YouTubers & Twitch streamers with decent monthly Patreon takes band together and fund it that way.